Ratchet handle for hoist



March 29, 1966 F. J. LOCK 3,242,747

RATCHET HANDLE FOR HoIsT Filed March 24. 1964 ATTOPA/EY United StatesPatent O 3,242,747 RATCHET HAN DLE FOR HGIST Frank I. Lock,Philadelphia, Pa., assignor to Yale & Towne, Inc., New York, N.Y., acorporation of hio Filed Mar. 24, 1964, Ser. No. 354,402 3 Claims. (Cl.74-157) This invention relates to a hoist having a ratchet handle orlever by which the hoist is operated. More particularly, the inventionrelates to the pawl arrangement for the ratchet handle.

Ratchet handles for hoists conventionally include either a reciprocatingpawl having a single pawl tooth for engagement with ratchet teeth on theoperating shaft of the hoist or a pivotally mounted pawl having two pawlteeth either of which may be engaged with the ratchet teeth. With thefirst type of pawl, the direction of operation of the hoist is reverse,by withdrawing and reversing the pawl. With the Second type of pawl, thedirection of operation of the hoist is reversed by pivoting the pawl toengage one or the other of the pawl teeth with the ratchet teeth. Of thetwo types of pawls, the second type is preferred, as it may be used witha ratchet having generally triangular shaped teeth, while the iirst typeof pawl requires a ratchet having generally square teeth. The triangularteeth provide easier engagement of the pawl with the teeth and allow agreater number of teeth to be used for the same sized ratchet, therebyproviding smaller increments of adjustment.

This invention provides an improved pawl arrangement of the second typewhich is simpler, less expensive and more efiicient than thoseheretofore used. To this end, the arrangement of the invention includestwo pawls, in contrast to the prior arrangements in which a single pawlis used with two pawl teeth. The two pawls of the arrangement of theinvention are mounted in crossed or scissors fashion on a common pivot,with the pawl teeth of the two pawls extending from one side of thepivot toward the ratchet teeth on the operating shaft of the hoist andextensions of the pawls extending from the other side of the pivot. Asingle, simple spring extends around the extensions of the pawls' andurges the extensions toward each other whereby to urge the pawl teethtoward each other. A cam member extends between the extensions of thepawls and in a neutral position holds the pawls out of engagement withthe ratchet teeth. When it is desired to engage one of the pawls withthe ratchet teeth, the cam is rotated to force the other pawl furtheraway from the ratchet teeth, while allowing the first pawl to be movedthrough the force of the spring into engagement with the ratchet teeth.If it is desired to engage the other pawl with the ratchet teeth, thecam is merely rotated in the opposite direction to force the rst pawlaway from the ratchet teeth whereby the spring forces the other pawlinto engagement with the ratchet teeth.

By this arrangement of two pawls mounted in scissors fashion with aspring extending around extensions of the pawls, the movement of onepawl away from the ratchet teeth by the cam actually increases the forcewith which the spring urges the other pawl into engagement with theratchet teeth thereby increasing the eiciency of the spring for thepurpose of engagement of the pawl. Further, with two pawls, if one ofthe pawls should break, only a small, single pawl has to be replaced.This, of course, is in contrast to the prior arrangement in which Vthelarge pawl with two pawl teeth must be replaced, if one of the pawlsteeth should break.

I have thus outlined rather broadly the more important features of myinvention in order that the detailed description thereof that followsmay be better understood,

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and in order that my contribution to the art may be better appreciated.There are, of course, additional features of my invention that will bedescribed hereinafter and which will form the subject of the claimsappended hereto. Those skilled in the art will appreciate that theconception on which my disclosure is based may readily be utilized as abasis for the designing of other structures for carrying out the severalpurposes of my invention. It is important, therefore, that the claims beregarded as including such equivalent constructions as do not departfrom the spirit and scope of my invention, in order to prevent theappropriation of my invention by those skilled in the art.

FIG. 1 is a side elevational view of a hoist incorporating a handle pawlarrangement constructed in accordance with the invention,

FIG. 2 is a sectional view taken on the line 2 2 of FIG. l,

FIG. 3 is a sectional view taken on the line 3 3 of FIG. 2,

FIG. 4 is a sectional view, similar to FIG. 3, but showing one of thepawls engaged with the ratchet teeth on the operating shaft, and

FIG. 5 is a perspective, exploded view of the two pawls, showing thestructure and assembly thereof.

Referring to the drawings and in particular to FIG. 1, there is shown ahoist 10 having a ratchet handle 11 incorporating a pawl arrangementconstructed in accordance with the invention. While not shown in thedrawings, the handle 11 is of substantial length to provide mechanicaladvantages in operating the hoist and allowing the operator to grasp thehandle with both hands.

Except for the pawl arrangement of handle 11 and the shape of theratchet teeth, the hoist 10 may be of any conventional constructionhaving an operating shaft, as shown at 12 in FIG. 2, which when rotatedin one direction effects lifting of a hook 13 through a chain 14 andwhen rotated in the opposite direction effects lowering of the hook 13.For example, the hoist con struction shown in my copending application,Serial No. 91,241, filed February 23, 1961, now Patent Number 3,138,231,may be used.

As best shown in FIGS. 2, 3 and 4, the operating shaft 12 has triangularshaped ratchet teeth 15 formed in the periphery thereof, and the end ofthe handle 11 is mounted for rotation of the shaft 12, with the shaft 12extending through an opening 16 formed through the end of the handle 11.The handle 11 is retained on the shaft 12 by a suitable retaining ring16a.

The pawl arrangement of the invention by which the handle 11 may beconnected to the operating shaft 12 so that the shaft 12 may be rotatedin either direction by short pumping strokes of the handle 11 includes,as best shown in FIGS. 3 and 4, two pawls 17 and 18. The two pawls 17and 18 are mounted in scissors fashion on a common pivot pin 19, withpawl teeth 20 and 21 thereof extending from one side of the pivot pin 19toward the ratchet teeth 15 on the operating shaft 12, and extensions 22and 23 of the pawls extending on the opposite side of the pivot pin 19.

A simple C-shaped spring 24 extends around the extensions 22 and 23 andurges the extensions 22 and 23 toward each other to urge the pawl teeth20 and 21 toward each other and toward the ratchet teeth 15. TheC-shaped spring 24 is held assembled to the pawls 17 and 18 byengagement of the ends of the spring in recesses 25 and 26 formed in thesides of the extensions 22, and 23 of the pawls.

As best shown in FIG. 5, the pawls 17 and 18 are made identical andprovided with cut-away portions 27 and 28 on one side thereof. Inassembling the pawls 17 and 18, one of the pawls is reversed and thepawls nested with the center portion 27 of one pawl received in the-cut-away portion 28 of the other pawl to reduce the overall thicknessof the assembled pawls while allowing relative pivotal movement betweenthe pawls.

The pawls 17 and 18, the pivot pin 19 and the spring 24 are assembled ina recess 29 formed in the side of the handle 11 which communicates withthe opening 16 through the handle. A cover plate 30 is secured to theside of the handle by screws 31 and covers the recess 29 to retain thepawls 17 and 18, the pivot pin 19 and the spring 24 within the recess29.

A shaft 32 is journaled at one end in the cover plate 30, extendsbetween the extensions 22 and 23 of the pawls 17 and 18 and through thebottom wall 33 of the recess 29 into a recess 34 formed in the oppositeside of the handle 11. A nger lever or knob 35 is secured to the end ofthe shaft 32 which extends into the recess 34 by means of a pivot pin36, whereby the shaft 32 may be rotated by turning of the lever or knob35.

As best shown in FIGS. 3, 4 and 5, the portion of the shaft 32 whichextends between the extensions 22 and 23 of the pawls 17 and 18 is cutaway at 37 and 3S leaving an eccentric cam portion 39. In either thedown or up position of the shaft 32, the cut-away portions 37 and 38provide clearance allowing the spring 24 to move either the pawl teeth21 or 22 out of engagement with the ratchet teeth 15. The cam portion 39prevents pivotal movement of the pawls 17 and 18 in a neutral position.In this neutral position of the pawls, the handle 11 may be rotatedfreely of the shaft 12, so that the operator may rotate the handle to aposition which is most convenient for operating the hoist.

If it is desired to lower the hook 13, the lever or knob 35 is rotatedin the counterclockwise direction, until the pointed end 35a of thelever 35 points to the word don/n" embossed on the side of the handle,as shown in FIG. 1. This results in rotation of the eccentric camportion 39 of the shaft 32 to the position shown in FIG. 4, resulting inthe tooth 21B of the pawl 17 being forced away from the ratchet teeth bythe cam portion 39 and the extension 23 of the pawl 18 being releasedwhereby the spring 24 forces the pawl tooth 21 of the pawl 18 intoengagement with the ratchet teeth 15 as shown in FIG. 4. On downwardpumping movement of the handle 11 the operating shaft 12 will be rotatedin the counterclockwise direction with a resulting lowering of the hook13. On the upward return stroke of the handle 11, the pawl 18 will rideover the teeth 15 through a yielding of the C-shaped spring 24.

Similarly, if the lever or knob 35 is turned in the counterclockwisedirection until the pointed end 35a thereof points to the word upembossed on the side of the handle as shown in FIG. 1, the eccentric camportion 39 will be rotated to a position forcing the pawl tooth 21 ofthe pawl 18 away from the ratchet teeth 15, while allowing the spring 24to force the pawl tooth 20 of the pawl 17 into engagement with theratchet teeth 15 whereby the handle 11 may be used to rotate theoperating shaft 12 in a clockwise direction to raise the hook 13.

From the preceding description, it can be seen that there is provided anovel pawl arrangement which is simpler, less expensive and more eicientthan those heretofore used. Because of the arrangement of the simpleC-spring extending around the extensions of the pawls, when one of thepawls is moved away from the ratchet teeth by the cam, the spring isactually tensioned, thereby increasing the force with which the springurges the other pawl into engagement with the ratchet teeth. T heefficiency of the spring for the purpose of engaging the pawl istherefore increased.

While one form of the invention has been shown and described, it will beunderstood that this is for the purpose of explanation and that changesVand modifications may be made therein without departing from the spiritand scope of the invention.

I now claim:

1. In a hoist having an operating shaft and a handle mounted forrotation on said shaft, ratchet teeth on said shaft, a pair of separatepawls, each pawl having a pawl tooth at one end and an extension at theother end, means mounting said pawls in scissors fashion on a commonpivot of said handle with the pawl tooth of each pawl extending from oneside of said pivot toward said ratchet teeth on said operating shaft andthe extension of each pawl extending from the other side of said pivot,C-shaped spring means extending around said extensions and urging saidextensions toward each other whereby to urge said pawl teeth toward eachother and toward said ratchet teeth, rotatable cam means extendingbetween said spring and said extensions of said pawls, said cam means inone rotated position preventing pivotal movement of either of said pawlteeth into engagement with said ratchet teeth, said cam means in secondand third rotated positions pivoting one of said pawls in a direction tomove the pawl tooth thereof further away from said ratchet teeth whilereleasing the other pawl for rotation by said C-shaped spring means in adirection to engage the pawl tooth thereof with the ratchet teeth ofsaid operating shaft whereby said operating shaft can be rotated in onedirection by said handle.

2. In a hoist having an operating shaft and a handle mounted forrotation on said shaft, ratchet teeth on said shaft, a pair of separatepawls, each pawl having a pawl tooth at one end and an extension at theother end, means mounting said pawls in scissors fashion on a commonpivot of said handle with the pawl tooth of each pawl extending from oneside of said pivot toward said ratchet teeth on Said operating shaft andthe extension of each pawl extending from the other side of said pivot,spring means extending around said extensions and urging said extensionstoward each other whereby to urge said pawl teeth toward each other andtoward said ratchet teeth, movable cam means extending between saidspring and said extensions of said pawls, said cam means in one positionpreventing pivotal movement of either of said pawl teeth into engagementwith said ratchet teeth, said cam means in second and third positionspivoting one of said pawls in a direction to move the pawl tooth thereoffurther away from said ratchet teeth while releasing the other pawl forrotation by said spring means in a direction to engage the pawl tooththereof with the ratchet teeth of said operating shaft whereby saidoperating shaft can be rotated in one direction by said handle.

3. In a hoist having an operating shaft and a handle mounted forrotation on said shaft, ratchet teeth on said shaft, a pair of pawls,each pawl having a pawl tooth at one end and an extension at the otherend, means mounting said pawls in scissors fashion on a common pivot ina recess formed in the side of said handle with the pawl tooth of eachpawl extending from one side of said pivot toward said ratchet teeth onsaid operating shaft and the extension of each pawl extending from theother side of said pivot, C-shaped spring means extending around saidextensions and urging said extensions toward each other whereby to urgesaid pawl teeth toward each other and toward said ratchet teeth, a coverfor said recess enclosing said pawls, spring, and pivot in said recess,rotatable cam means extending between said spring and said extensions ofsaid pawls, shaft means connected with said cam means and extending fromone side of said handle, lever means secured to said shaft means on theoutside of said handle for rotating said shaft to rotate said cam means,said Cam means in one rotated position preventing pivotal movement ofeither of said pawl teeth into engagement with said ratchet teeth, saidcam means in second and third rotated positions pivotiing one of saidpawls in a direction to move the pawl tooth thereof further away fromsaid ratchet teeth while releasing the other pawl for rotation by saidspring means in a direction to engage the pawl tooth thereof with theratchet teeth of said 5 operating shaft whereby said operating shaft canbe rotated 2,608,107 in one direction by said handle. 2,627,7572,634,630 References Cited by the Examiner 3,120,131 UNITED STATESPATENTS 5 3'138231 844,356 2/ 1907 Hegerhorst 74-157 X 875,493 12/1907Beard 192 43.1 X 9801335 1,106,752 8/1914 Tomberg 74-157 3,495 1,368,3942/1921 Guthrie 74-157 X 10 584,232 2,367,208 1/1945 Garand 74-1572,507,681 5/1950 sage 74-157 2,508,568 5/1950 Ellison 74-157 6 8/ 1952Robins 74--578 2/1953 Austin 74-157 X 4/1953 Johnson 74-157 X 2/1964Simonds 74-157 6/1964 Lock 192-16 FOREIGN PATENTS 12/1950 France.

1/ 1879 Germany. 1/ 1947 Great Britain.

BROUGHTON G. DURHAM, Primary Examiner. J. A. MATHEWS, D. P. ROONEY,Assistant Examiners.

1. IN A HOIST HAVING AN OPERATING SHAFT AND A HANDLE MOUNTED FORROTATION ON SAID SHAFT, RATCHET TEETH ON SAID SHAFT, A PAIR OF SEPARATEPAWLS, EACH PAWL HAVING A PAWL TOOTH AT ONE END AND EXTENSION AT THEOTHER END, MEANS MOUNTING SAID PAWLS IN SCISSORS FASHION ON A COMMONPIVOT OF SAID HANDLE WITH THE PAWL TOOTH OF EACH PAWL EXTENDING FROM ONESIDE OF SAID PIVOT TOWARD SAID RATCHET TEETH ON SAID OPERATING SHAFT ANDTHE EXTENSION OF EACH PAWL EXTENDING FROM THE OTHER SIDE OF SAID PIVOT,C-SHAPED SPRING MEANS EXTENDING AROUND SAID EXTENSIONS AND URGING SAIDEXTENSIONS TOWARD EACH OTHER WHEREBY TO URGE SAID PAWL TEETH TOWARD EACHOTHER AND TOWARD SAID RATCHET TEETH, ROTATABLE CAM MEANS EXTENDINGBETWEEN SAID SPRING AND SAID EXTENSIONS OF SAID PAWLS, SAID CAM MEANS INONE ROTATED POSITION PREVENTING PIVOTAL MOVEMENT OF EITHER OF SAID PAWLTEETH INTO ENGAGEMENT WITH SAID RATCHET TEETH, SAID CAM MEANS IN SECONDAND THIRD ROTATED POSITIONS PIVOTING ONE OF SAID PAWLS IN A DIRECTION TOMOVE THE PAWL TOOTH THEREOF FURTHER AWAY FROM SAID RATCHET TEETH WHILERELEASING THE OTHER PAWL FOR ROTATION BY SAID C-SHAPED SPRING MEANS IN ADIRECTION TO ENGAGE THE PAWL TOOTH THEREOF WITH THE RATCHET TEETH OFSAID OPERATING SHAFT WHEREBY SAID OPERATING SHAFT CAN BE ROTATED IN ONEDIRECTION BY SAID HANDLE.